1. Field of the Invention
The present invention relates to a substrate treating apparatus and method (for example, a sheet-feed type substrate cleaning apparatus for cleaning a plurality of wafers fed sheet by sheet) having a recovery system for a substrate treating medium such as a substrate cleaning liquid or the like. More specifically, it relates to a technology for improving a recovery rate of the substrate treating medium.
2. Description of the Related Art
Conventionally, a substrate treating or processing apparatus having a system for cleaning substrates such as silicon wafers by means of a cleaning liquid and recovering the same has been known, an example of which is described in Japanese Patent Laid-Open No. Hei 8-130202.
The substrate treating apparatus includes, as a wafer cleaning system (Bernoulli cleaning mechanism), an upper cleaning plate disposed in opposition to an upper surface of a wafer, a lower cleaning plate disposed in opposition to a lower surface of the wafer, and a wafer holder of a cylindrical configuration having an inner diameter equal to an outer diameter of the wafer. The wafer is held in a horizontal state thereof by the wafer holder with its outer periphery being in contact with an inner peripheral surface of the wafer holder. The upper and lower cleaning plates are disposed in parallel with the upper and lower surfaces, respectively, of the wafer for ejecting a cleaning liquid thereto, whereupon the wafer holder is driven to rotate, thus causing the wafer held thereby to rotate.
A portion of the cleaning liquid ejected from the center of the upper cleaning plate passes through a space defined between the upper cleaning plate and the wafer to flow out from between the outer periphery of the upper cleaning plate and the outer periphery of the wafer upper surface, whereas another portion of the cleaning liquid ejected from the center of the lower cleaning plate passes through a space defined between the lower cleaning plate and the wafer to flow out from the outer periphery of the lower cleaning plate and the outer periphery of the wafer lower surface.
With the above-mentioned substrate treating apparatus, a mechanism is required for preventing the cleaning liquid flowing out of the outer peripheries of the wafer upper and lower surfaces from splashing or scattering into the surroundings, as described above. To this end, for example, it may be beneficial to provide a cover for covering the whole of the upper and lower cleaning plates and the wafer holder.
In practice, however, such a cover is required to have, in addition to the function of merely preventing the splashing or scattering of the cleaning liquid, further functions of recovering the used cleaning liquid in an efficient manner and preventing those portions of the cleaning liquid which are left attached as liquid mists or droplets to the wafer holder, the cover and the like after cleaning from being again attached to the wafer that has been cleaned. If the cleaning liquid is attached to the once cleaned wafer, it would cause formation of cleaning spots, water marks and the like.
In view of the above, the present invention is intended to obviate the above-mentioned problems encountered with the conventional apparatus and has for its object to provide a substrate treating apparatus and method which are capable of recovering a substrate treating medium such as a cleaning liquid in an efficient manner and which can positively avoid occurrences of treatment defects such as formation of cleaning spots, water marks and the like.
Bearing the above object in mind, according to a first aspect of the present invention, there is provided a substrate treating apparatus comprising: a fixed upper plate; a fixed lower plate disposed in opposition to the fixed upper plate; a mechanism for supporting a substrate at a location in a space defined between the fixed upper and lower plates, rotating the substrate and introducing a substrate treating medium (e.g., a cleaning liquid) into the space to treat the substrate while the substrate is rotating: a discharge passage through which the substrate treating medium is discharged from the space; and rotary blades disposed in the discharge passage and adapted to rotate in accordance with the rotation of the substrate, thereby enhancing discharging of the substrate treating medium from the space through the discharge passage.
With this construction, the rotary blades disposed in the discharge passage draw the substrate treating medium in a direction to discharge it, thus improving the discharging of the substrate treating medium.
According to a second aspect of the present invention, there is provided a substrate treating apparatus comprising: a fixed upper plate; a fixed lower plate disposed in opposition to the fixed upper plate; a support for supporting a substrate at a location in a space defined between the fixed upper and lower plates, the support being rotatable and having an outer peripheral surface (e.g., an outer peripheral surface of an outer ring); a housing having an inner surface and covering the outer peripheral surface of the support; a drive mechanism for rotating the support together with the substrate and introducing a substrate treating medium into the space to treat the substrate while the substrate is rotating; a discharge passage defined between the outer peripheral surface of the support and the inner surface of the housing for discharging the substrate treating medium from the space; first vanes (e.g., rotary blades) provided on the outer peripheral surface of the support for enhancing discharging of the substrate treating medium from the space through the discharge passage; and second vanes (e.g., stationary blades) provided on the inner surface of the housing for enhancing, in cooperation with the first vanes, the discharging of the substrate treating medium from the space through the discharge passage.
In a preferred mode of the second aspect of the invention, the second vanes (e.g., stationary blades) are disposed at locations downstream of the first vanes (e.g., rotary blades) in a direction in which the substrate treating medium is to be discharged.
In another preferred mode of the second aspect of the invention, the first vanes (e.g., rotary blades) and/or the second vanes (e.g., stationary blades) are inclined so as to guide the substrate treating medium in a direction to discharge it.
In a further preferred mode of the second aspect of the invention, the first vanes (e.g., rotary blades) and the second vanes (e.g., stationary blades) are inclined in opposite directions with respect to each other.
In a still further preferred mode of the second aspect of the invention, the first vanes (e.g., rotary blades) and the second vanes (e.g., stationary blades) are inclined in opposite directions with respect to each other at an angle of 45 degrees with respect to the discharging direction.
In a yet further preferred mode of the second aspect of the invention, the support (e.g., substrate chuck pins of a substrate support) serves to support the substrate at its upper end, and each of the first vanes (e.g., rotary blades) has an upper end thereof positioned at a location higher than an upper surface of the substrate.
In a further preferred mode of the second aspect of the invention, the first vanes provided on the outer peripheral surface of the support is rotatable in unison with the support.
In a further preferred mode of the second aspect of the invention, the second vanes are fixedly secured to the inner surface of the housing.
In a further preferred mode of the second aspect of the invention, the second vanes provided on the inner surface of the housing are rotatable in a direction opposite the direction in which the first vanes rotate.
In a further preferred mode of the second aspect of the invention, the first vanes provided on the outer peripheral surface of the support rotate at a speed higher than that of the support.
In a further preferred mode of the second aspect of the invention, third vanes (e.g., threaded screws) are provided on the outer peripheral surface of the support on which the first vanes are provided.
In a further preferred mode of the second aspect of the invention, the third vanes (e.g., threaded screws) are disposed at locations downstream of the first vanes (e.g., rotary blades) and the second vanes (e.g., stationary blades) in a direction in which the substrate treating medium is to be discharged.
In a further preferred mode of the second aspect of the invention, a plurality of sets of assemblies are provided each of which comprises the first vanes, the second vanes and the third vanes, the sets of assemblies being disposed in the discharging direction.
According to a third aspect of the present invention, there is provided a substrate treating method comprising: inserting a substrate into a space defined between a fixed upper plate and a fixed lower plate; introducing a substrate treating medium into the space; rotating the substrate in the space; rotating rotary blades in a discharge passage, through which the substrate treating medium is to be discharged, in accordance with the rotation of the substrate; and discharging the substrate treating medium from the space through the discharge passage under a discharging action of the rotary blades.
According to a fourth aspect of the present invention, there is provided a substrate treating method comprising: inserting a substrate into a space defined between a fixed upper plate and a fixed lower plate; introducing a substrate treating medium into the space; rotating the substrate through a support which supports the substrate; discharging the substrate treating medium from the space through a discharge passage defined between an outer peripheral surface of the support and an inner surface of a housing which covers the outer peripheral surface of the support; and discharging, during the discharging of the substrate treating medium, the substrate treating medium through cooperation of first vanes provided on the outer peripheral surface of the support for enhancing a discharging operation of the discharge passage and second vanes provided on the inner surface of the housing for enhancing the discharging of the substrate treating medium.
In a preferred mode of the fourth aspect of the invention, the second vanes are disposed at locations downstream of the first vanes in a direction in which the substrate treating medium is to be discharged.
In another preferred mode of the fourth aspect of the invention, the first vanes and/or the second vanes are inclined so as to guide the substrate treating medium in the discharging direction.
In a further preferred mode of the fourth aspect of the invention, the first and second vanes are inclined in opposite directions with respect to each other.
According to the substrate treating method of the invention as described above, the rotary blades disposed in the discharge passage draw the substrate treating medium in a direction to discharge it, thus improving the discharging of the substrate treating medium and permitting the substrate treating medium such as a cleaning liquid to be recovered efficiently.
The above and other objects, features and advantages of the present invention will become more readily apparent to the those skilled in the art from the following detailed description of a preferred embodiment of the invention taken in conjunction with the accompanying drawings.